Magnetic pickup device



1967 J. E. LARRISON ETAL 3,297,352

MAGNETIC PICKUP DEVICE Filed Aug. 50. 1965 Fig. t 38 John E. Lurrison,

Bob G. Bender,

INVENTORS.

(Juli fi- ATTORNEY.

United States Patent Company, Culver City, Calif., a corporation ofDelaware Filed Aug. 30, 1965, Ser. No. 483,548 3 Claims. (Cl. 294-655)This invention relates to a magnetic pickup device and more particularlyto a magnetic pickup device for positioning small semiconductor elementsin holes in a circuit board;

The increased use of subminiature and micro-electronic circuits hasintroduced to the electronic industry the problem of handling extremelysmall electronic components such as semiconductor diodes. Typically,such components have a diameter of .062 inch and a thickness of .038inch, and because of this miniature size have been handled withtweezers. While such handling has proven satisfactory for someoperations, it has been found'difi'icult to pick up with a pair oftweezers such small items and position them in small holes in circuitboards.

Therefore, it is an object of the present invention to provide animproved magnetic pickup device for picking up extremely small objects.

A further object of the improved magnetic pickup device is to provide adevice for picking up small semiconductor elements having metallic edgesand positioning them in holes in circuit boards.

A still further object is to provide an improved magnetic pickup devicefor small semiconductor elements which is simple to operate and can beused to efiiciently assemble such elements at increased assembly rates.

Other advantages of the invention will hereinafter become more fullyapparent from the following description of the drawings which illustratea preferred embodiment thereof and in which:

FIGURE 1 is a front elevational view of the improved magnetic pickupdevice illustrating the configuration of the device to facilitate thegripping of it by the operators hand;

FIG. 2 is an enlarged view of a portion of the improved pickup device ofthe present invention shown in cross section illustrating the taperedpoint, the magnetic element and the resilient pad; and

FIG. 3 is a perspective view of a portion of a circuit board and the endof the magnetic pickup device of the present invention showing asemiconductor element positioned in a hole therein having its electrodecaps in contact with conductors on the circuit board.

Briefly, the magnetic pickup device of the present invention comprisesan elongated cylindrical body configured for gripping between thefingers of the hand in a pencil-like fashion. A tapered point having ablunt end is aflixed to one end of the body and extending inwardly fromthe blunt end is a chamber which has a chamfered edge. A magneticelement is positioned in the chamber and is retained therein by aresilient plug. The plug has a slightly larger diameter than the chamberso that it can be wedged or forced into the chamber into engagement withthe magnetic element and is positioned in the chamber sufficientlyinward from the blunt end to define along with the chamfered edge adished recess or detent.

Referring now to FIGS. 1 and 2, the magnetic pickup device of thepresent invention comprises an elongated generally cylindrical bodywhich may be made of a plastic material. The body includes a pluralityof grooves 12 near a tapered end 14. These grooves 12 are generallyshaped and spaced in a manner to facilitate the 3,297,352 Patented Jan.10, 1967 gripping of the body 10 by the fingers of the hand in apencil-like fashion. A tapered point 16 of a metallic non-magneticmaterial such as stainless steel is ailixed to the body 10 by pressfitting a protruding portion 18 thereof into a bore 20 in the end of thebody. The point has 7 a blunt tip 22 which defines one end of a chamber24 extending coaxially into the point 16 and including a chamfered edge26.

A magnetic element 28 such as a permanent magnet having an elongatedcylindrical shape such as an Alnioo magnet li inch in diameter and inchlong manufactured by General Electric Company is inserted into thechamber 24. Because of the elongated shape of the magnetic element, themagnetic lines of force are caused t concentrate immediately adjacent tothe blunt tip 22 of the point 16.

To retain the magnetic element 28 in the chamber 24 tween the pickupdevice and the object to be picked up, a resilient plug 30 of amate-rial such as rubber having a diameter slightly greater than that ofthe chamber is inserted into and held by the wall of the chamber 24. Theplug 30 is positioned in the chamber sufficiently inward from the blunttip 22 so that along with the charnfered edge 26 of the chamber 24 itdefines a slight recess or detent 32 in the blunt tip 22.

Referring to FIG. 3, the magnetic device of the present invention isadapted in a preferred embodiment to the picking up and positioning of asemiconductor element 34 having a generally cylindrical shape and a pairof metallic electrode cap elements 36. In the preferred embodiment ofthe device, the detent 32 has a diameter sufficient to permit thesemiconductor element 34 to be inserted in the detent 32 into contactwith the rubber pad 30 and held therein by the magnetic force of themagnetic element 28. In this fashion, the pickup device may bepositioned over the semiconductor element in a specific orientationsince the metal electrodes 36 will both be held in contact with therubber pad 30 by the magnetic force. Such orientation permits thesemiconductor element to be positioned in a hole 37 in a circuit board38 with the electrodes 36 in contact with the ends of conductors 40forming a portion of the periphery of the hole 37. When thesemi-conductor element is so inserted, the friction force between theengaging metal portions is enough to retain the element in the hole andto permit the pickup device to be pulled away from engagement therewith,thus disengaging the element from in contact with the blunt tip 16.

While one embodiment of this invention has been herein illustrated, itshould be appreciated by those skilled in the art that variations of thedisclosed arrangement both as to its details and the operation of suchdetails may be made without departing from the skill and scope thereof.Accordingly, it is intended that the fore-going disclosure and theshowings made in the drawings may be considered as illustrative of thisinvention and not construed in a limited sense.

What is claimed is:

1. A magnetic pickup device comprising:

an elongated cylindrical body shaped for gripping between the fingers ofthe hand in a pencil-like fashion;

a tapered point afiixed to one end of the body and including a blunt tipdefining the end of a chamber having a chamfered edge;

an elongated magnetic element retained in said cham ber and having anexposed end positioned inwardly from said blunt tip; and

a resilient plug of slightly larger diameter than said chamber wedgedinto said chamber into engagement with said magnetic element, said plugbeing inserted v 3 4 into said chamber sufficiently to define with saidReferences Cited by the Examiner chamfered edge a detent. 2. A magneticpickup device according to claim 1 UNITED STATES PATENTS adapted formanual operation wherein the cylindrical 2,993,723 7/1961 Twachtman 5body includes a portion configured for gripping between '5 3 169 7912/1965 Twachtman the fingers of the hand.

3. A magnetic pickup device according to claim 1 wherein said detent isof a configuration to engage a GERALD FORLENZA, P Timmy Exammercylindrical semiconductor having metallic portions With G F ABRAHAMAssistant Examiner said portions engaging said resilient plug. 10

1. A MAGNETIC PICKUP DEVICE COMPRISING: AN ELONGATED CYLINDRICAL BODYSHAPED FOR GRIPPING BETWEEN THE FINGERS OF THE HAND IN A PENCIL-LIKEFASHION; A TAPERED POINT AFFIXED TO ONE END OF THE BODY AND INCLUDING ABLUNT TIP DEFINING THE END OF A CHAMBER HAVING A CHAMFERED EDGE; ANELONGATED MAGNETIC ELEMENT RETAINED IN SAID CHAMBER AND HAVING ANEXPOSED END POSITIONED INWARDLY FROM SAID BLUNT TIP; AND A RESILIENTPLUG OF SLIGHTLY LARGER DIAMETER THAN SAID CHAMBER WEDGED INTO SAIDCHAMBER INTO ENGAGEMENT WITH SAID MAGNETIC ELEMENT, SAID PLUG BEINGINSERTED INTO SAID CHAMBER SUFFICIENTLY TO DEFINE WITH SAID CHAMFEREDEDGE A DETENT.